Railway Previous Year GK Questions with Answers

The correct answer is B, Iron rod. An iron rod is a solid, and the force of attraction between particles is strongest in the solid state.

In a solid the particles sit close together in fixed positions and can only vibrate, so a solid keeps its shape, has a definite volume and can hardly be compressed. In a liquid the attraction is weaker, so the particles slide over one another and the liquid takes the shape of its vessel while keeping its volume. In a gas the attraction is weakest and the particles move freely at high speed, so a gas fills any container and is easily compressed. The same order explains why solids have the highest density and gases the lowest.

Option A is wrong because water is a liquid with medium attraction. Option C is wrong because alcohol is also a liquid, and it evaporates faster than water. Option D is wrong because oxygen is a gas, where the attraction between particles is the weakest of all.

Exam tip: force of attraction is solid greater than liquid greater than gas, and the freedom of particles runs the other way.

The correct answer is C, 500 W. The work done against gravity is mgh = 40 × 10 × 5 = 2000 joule, and power is work divided by time, so 2000 ÷ 4 = 500 watt.

Power is the rate of doing work, measured in watt, where one watt is one joule per second. In climbing stairs the useful work is the gain in potential energy, mgh, where only the vertical rise counts and the length of the staircase does not matter. If the same girl ran up in 2 seconds the work would be the same 2000 joule but the power would double to 1000 watt, which shows that power depends on how fast the work is done.

Option A is wrong because 100 W comes from dividing by the wrong quantity. Option B is wrong because 200 W would need 10 seconds. Option D is wrong because 2000 is the work in joule, not the power in watt.

Exam tip: work = mgh, power = work ÷ time, and one horsepower is about 746 watt.

The correct answer is C, Breaking a chalk stick. Force has to be applied to break the chalk because its particles hold one another together, and that pull is the force of attraction between particles.

Every substance is made of particles that attract one another, and the strength of that attraction decides how hard a thing is to break. The attraction is strongest in solids, less in liquids and least in gases, which is why an iron rod needs a hammer, water can be separated with a finger and air offers no resistance at all. The school activity of breaking chalk, then a pencil and then an iron nail shows the difference in this force from one solid to another.

Option A is wrong because compressing a sponge only squeezes out the air in its pores. Option B is wrong because dissolving sugar shows diffusion and the spaces between particles. Option D is wrong because heating ice shows a change of state, not the attraction itself.

Exam tip: attraction between particles is strongest in solids, weaker in liquids and weakest in gases.

The correct answer is C, zero. Constant velocity means no acceleration, and by Newton's second law force equals mass into acceleration, so the net force must be zero.

Newton's first law says a body continues in its state of rest or of uniform motion in a straight line unless an external force acts on it, which is why motion at a steady speed in a fixed direction needs no force to keep it going. Force is needed only to change the speed or the direction. A car moving at a steady 60 km per hour on a straight road is in the same state: the engine's push only balances friction and air resistance, so the forces cancel and the net force is zero. Such a body is said to be in equilibrium.

Options A, B and D are wrong because any net force in a direction would produce acceleration and so change the velocity, which contradicts the given condition of constant velocity.

Exam tip: constant velocity means zero acceleration and therefore zero net force, not zero force at all.

The correct answer is B, Platinum. Platinum is the least reactive of the four, so it is found in nature in the free or native state as the metal itself.

A metal occurs free only when it does not react with the air, water and other substances around it. In the reactivity series the metals at the bottom - gold, platinum and silver - are called noble metals and are found native; those higher up occur as oxides, sulphides or carbonates and must be extracted from their ores. This is why gold nuggets are found in river sand while aluminium has to be won from bauxite by electrolysis.

Option A is wrong because copper is mostly mined as copper pyrites and other ores, though small native deposits do exist. Option C is wrong because iron is always found as an oxide such as haematite or magnetite. Option D is wrong because potassium is so reactive that it burns on contact with water and is never found free.

Exam tip: gold, platinum and silver occur native; the more reactive a metal, the more firmly it stays locked in its ore.

The correct answer is C, Manipur. M. C. Mary Kom was born in Kangathei village of Churachandpur district in Manipur.

Mary Kom is the only woman boxer to have won six world championship titles, and she is nicknamed Magnificent Mary. She took the bronze medal in the flyweight class at the London Olympics of 2012, the first Indian woman boxer to win an Olympic medal, and she has also won gold at the Asian Games of 2014 and the Commonwealth Games of 2018. She received the Arjuna Award, the Padma Shri, the Rajiv Gandhi Khel Ratna and the Padma Vibhushan, and served as a nominated member of the Rajya Sabha.

Option A is wrong because Mizoram is best known in Indian sport for footballers. Option B is wrong because Assam is the home state of the boxer Shiva Thapa and the sprinter Hima Das. Option D is wrong because Meghalaya has produced no boxer of this record.

Exam tip: Mary Kom of Manipur, six world titles, bronze at London 2012, called Magnificent Mary.

The correct answer is D, Intermolecular forces are weak. Melting and boiling only have to break the weak forces between the molecules, not the strong bonds inside them, so little heat is needed.

A covalent bond is formed by the sharing of electrons and is itself strong, but it acts only within the molecule. Separate molecules are held to one another by weak van der Waals forces, and these give way at low temperature, which is why water, ammonia, carbon dioxide and most organic compounds melt and boil easily. Ionic compounds such as sodium chloride behave in the opposite way: a strong electrostatic force runs through the whole crystal, so their melting points are very high. Giant covalent solids like diamond and silicon carbide are the exception, since their bonds form a continuous network.

Options A, B and C are wrong because they all claim the forces between molecules are medium or strong, which would raise the melting and boiling points instead of lowering them.

Exam tip: strong bond inside the molecule, weak force between molecules, so covalent compounds melt at low temperature.

The correct answer is C, 24 J. By the work-energy theorem the work done equals the change in kinetic energy, which is half of 1.0 into 8 squared minus 4 squared, that is 0.5 × (64 - 16) = 24 joule.

Kinetic energy is given by half m v squared, so at 4 m/s the object has 8 joule and at 8 m/s it has 32 joule; the force must supply the difference of 24 joule. Note that doubling the speed makes the kinetic energy four times, because the speed is squared. The work-energy theorem holds whatever the path taken, which is why the question can be solved without knowing the force or the distance.

Option A is wrong because 8 joule is only the starting kinetic energy. Option B is wrong because 32 joule is the final kinetic energy, not the change. Option D is wrong because 16 joule comes from taking half of the difference of the squares of the speeds incorrectly.

Exam tip: work done = final kinetic energy minus initial kinetic energy, and doubling speed makes kinetic energy four times.

The correct answer is D, Lead and tin. Solder is an alloy of lead and tin, usually in nearly equal parts.

An alloy is a mixture of a metal with one or more other elements, made to gain a property the pure metal lacks. Solder is useful because the mixture melts at a far lower temperature than either lead or tin alone, so it flows easily and is used to join wires and electrical joints. Other alloys asked in papers are brass, made of copper and zinc, bronze of copper and tin, stainless steel of iron, chromium and nickel, and German silver of copper, zinc and nickel.

Option A is wrong because lead with copper is not the soldering alloy. Option B is wrong because tin with iron gives tin plating, used for tin cans. Option C is wrong because lead and iron together are not used as solder.

Exam tip: solder is lead plus tin and melts at a low temperature; brass is copper and zinc, bronze is copper and tin.

The correct answer is D, Madhya Pradesh. The Bansagar Dam stands on the Sone river in the Shahdol region of Madhya Pradesh.

Bansagar is a joint project of Madhya Pradesh, Uttar Pradesh and Bihar, the three states through which the Sone flows, and it serves both irrigation and power. The Sone is a major right bank tributary of the Ganga; it rises near Amarkantak, the same highland that gives birth to the Narmada, and joins the Ganga near Patna. The dam is named after the sage Bana, who is linked in tradition with the Sone valley.

Option A is wrong because Maharashtra has Koyna and Jayakwadi. Option B is wrong because Gujarat has the Sardar Sarovar on the Narmada and Ukai on the Tapi. Option C is wrong because Andhra Pradesh has Nagarjuna Sagar and Srisailam on the Krishna.

Exam tip: Bansagar on the Sone in Madhya Pradesh, shared with Uttar Pradesh and Bihar; Amarkantak is the source of both the Narmada and the Sone.

The correct answer is A, Tsunami. A tsunami is caused by an undersea earthquake, a volcanic eruption or a landslide on the ocean floor, and has nothing to do with the ozone layer.

The ozone layer lies in the stratosphere, roughly 15 to 35 km above the ground, and absorbs most of the harmful ultraviolet radiation of the Sun. Chlorofluorocarbons used in refrigerators, air conditioners and aerosol sprays release chlorine that destroys ozone, which is why the Montreal Protocol of 1987 phased them out. World Ozone Day is observed on 16 September.

Option B is a real result, because extra ultraviolet radiation damages skin cells and raises the risk of skin cancer. Option C is a real result, since a thinner layer lets more ultraviolet rays reach the Earth. Option D is a real result, as ultraviolet exposure weakens the immune system, and it also causes cataract and harms crops and plankton.

Exam tip: ozone holes bring skin cancer, cataract and weak immunity; tsunamis come from the sea floor, not the sky.

The correct answer is C, Kesari. Bal Gangadhar Tilak started Kesari in 1881 and used it to carry the message of swaraj to Marathi readers.

Tilak brought out two papers from Pune in the same year, Kesari in Marathi and Maratha in English. His writings in Kesari on the Bengal partition and on the Muzaffarpur bomb case led to a charge of sedition, and in 1908 he was sentenced to six years of transportation to Mandalay in Burma. It was Tilak who declared that swaraj is my birthright and I shall have it, and he began the public Ganapati and Shivaji festivals to reach ordinary people.

Option A is wrong because Yugantar was started in Bengali by Barindra Kumar Ghosh and Bhupendranath Datta. Option B is wrong because the Bengalee was edited by Surendranath Banerjee. Option D is wrong because Amrita Bazar Patrika was founded by Sisir Kumar Ghosh and Motilal Ghosh.

Exam tip: Tilak - Kesari in Marathi and Maratha in English; Gandhi - Young India and Navajivan.

The correct answer is B, USA. The World Bank has its headquarters at Washington DC in the United States of America.

The World Bank and the International Monetary Fund were both set up after the Bretton Woods conference of 1944 and began work in 1945, and both have their offices in Washington DC. The Bank lends for long-term development - roads, power, irrigation, schools and health - while the IMF looks after exchange rates and short-term balance of payments trouble. The World Bank Group has five arms, of which the IBRD and the IDA together form the World Bank, and India was a founder member.

Option A is wrong because London holds the Commonwealth Secretariat and the International Maritime Organisation, not the World Bank. Option C is wrong because Tokyo is the seat of the United Nations University, while the Asian Development Bank is at Manila. Option D is wrong because Moscow hosts no such global lender.

Exam tip: World Bank and IMF at Washington DC, WTO at Geneva, ADB at Manila.

The correct answer is D, uterus. The zygote divides as it travels down the fallopian tube and the resulting ball of cells gets implanted in the thick lining of the uterus.

Fertilisation itself takes place in the fallopian tube, where a sperm fuses with the ovum to form the zygote. Repeated division turns it into an embryo, which reaches the uterus in about a week and sinks into the endometrium, the soft inner wall prepared by hormones. There the placenta develops and supplies the growing embryo with food and oxygen from the mother's blood while carrying away waste. Human pregnancy lasts about nine months.

Option A is wrong because the cervix is only the narrow neck of the uterus that opens into the vagina. Option B is wrong because the ovary produces the ovum and hormones but does not hold the embryo. Option C is wrong because the vagina is the passage that receives the sperm and later serves as the birth canal.

Exam tip: fertilisation in the fallopian tube, implantation in the uterus, nourishment through the placenta.

The correct answer is D, money. Consumer theory studies how a household decides to spend its money among the goods and services available to it.

The idea rests on three things: the wants of the consumer, the prices of goods, and the income in hand, which is the budget constraint. Since income is limited, the consumer chooses the basket that gives the greatest satisfaction, or utility, from the money spent, and is said to be in equilibrium when no rearrangement of spending can raise that satisfaction. The law of diminishing marginal utility, indifference curves and the law of demand all belong to this branch of microeconomics.

Option A is wrong because the use of time is studied separately as the labour-leisure choice. Option B is wrong because relations are social, not economic, choices. Option C is wrong because energy here has no economic meaning as a thing the consumer allocates.

Exam tip: consumer theory joins three things - wants, prices and income - and explains the demand curve.

The correct answer is C, Mughal. Humayun's Tomb in Delhi is one of the earliest and finest examples of Mughal architecture.

The tomb was built in 1570 on the orders of Humayun's widow Bega Begum, also called Haji Begum, and the architect was Mirak Mirza Ghiyas of Persia. It was the first garden tomb in India, set in a charbagh, the four-part garden divided by water channels, and the first large structure to use red sandstone with white marble inlay and a high double dome. This plan became the model for the Taj Mahal built about eighty years later. UNESCO placed the tomb on the World Heritage list in 1993.

Option A is wrong because British architecture in India belongs to the colonial period after the eighteenth century. Option B is wrong because Chola architecture means Dravidian temples such as the Brihadeshwara temple at Thanjavur. Option D is wrong because Magadha is an ancient kingdom, not a style of tomb building.

Exam tip: Humayun's Tomb is the first garden tomb of India and the model for the Taj Mahal.

The correct answer is A, To consider cases of civil and criminal nature. Subordinate courts are the courts at the district level and below, and they hear civil and criminal cases as courts of first instance.

The Indian judiciary is a single pyramid. The Supreme Court stands at the top, a High Court in each state comes next, and below it are the subordinate courts, which work under the control of that High Court. On the civil side the District Judge is the highest, and below come the courts of the Civil Judge; on the criminal side the Sessions Judge is the highest, with Judicial Magistrates below. Articles 233 to 237 deal with these courts, and the Governor appoints district judges in consultation with the High Court.

Option B is wrong because writs are issued by the Supreme Court under Article 32 and by High Courts under Article 226. Option C is wrong because hearing appeals from lower courts is mainly the work of the High Court. Option D is wrong because transferring cases is a power of the higher courts.

Exam tip: District and Sessions Courts are subordinate courts; writs belong only to the Supreme Court and the High Courts.

The correct answer is B, 19.8 × 10⁶ J. One kilowatt hour is 3.6 × 10⁶ joule, so 5.5 kWh = 5.5 × 3.6 × 10⁶ = 19.8 × 10⁶ joule.

The kilowatt hour is the commercial unit of electrical energy, the unit in which the electricity board bills a house, and it is often called one unit of electricity. It comes from energy = power × time, so one kilowatt of power drawn for one hour means 1000 watt × 3600 second = 3600000 joule. The joule is the SI unit of energy, and one watt is one joule per second.

Option A is wrong because 14.0 × 10⁶ J is about 3.9 kWh. Option C is wrong because 14.4 × 10⁸ J would be 400 kWh, a hundred times too large. Option D is wrong because 14.4 × 10⁵ J is only 0.4 kWh.

Exam tip: 1 kWh = 3.6 × 10⁶ J = one unit of electricity; multiply the number of units by 3.6 million to get joule.

The correct answer is B, Kinetic energy + Potential energy. The mechanical energy of a body is the sum of the energy of its motion and the energy of its position. Kinetic energy is half m v squared and gravitational potential energy is mgh, and their total stays the same as long as only gravity acts and friction is absent. That is the law of conservation of mechanical energy: a ball thrown upward loses kinetic energy and gains exactly as much potential energy, and a falling ball does the reverse, which is why a simple pendulum keeps swinging between the same two heights. When friction or air resistance acts, part of the mechanical energy turns into heat and sound, so it is no longer conserved, although the total energy of the system still is. Option A is wrong because chemical energy is stored in the bonds of fuels and food. Option C is wrong because heat is the energy of random molecular motion and is counted separately. Option D is wrong because electrical energy comes from moving charges. Exam tip: mechanical energy equals KE plus PE, and it stays constant only when no friction acts.

The correct answer is B, kinetic energy. A stretched bow stores elastic potential energy, and when the string is released that store becomes the kinetic energy of the flying arrow. Potential energy is the energy held by a body because of its position or its shape. Pulling the string changes the shape of the bow, so the work done by the archer is stored as elastic potential energy, the same kind of store found in a compressed spring or a wound watch spring. On release the bow springs back to its old shape and pushes the arrow forward, so the stored energy turns into energy of motion. A small part does escape as the twang of sound and as heat, but the main change is potential to kinetic. Option A is wrong because chemical energy is stored in the bonds of fuels and food, not in a bent bow. Option C is wrong because the sound is only a small loss, not the main conversion. Option D is wrong because heat is likewise a minor loss here. Exam tip: a stretched bow, a compressed spring and a drawn catapult all store elastic potential energy.